Diffusion transfer reception elements,film units and processes therefor

ABSTRACT

Vinyl polymers containing anionic solubilizing groups are employed as the binder in a light-reflective layer which is associated with a dye image-receiving layer employed in color diffusion transfer systems.

United States Patent [191 Becker et al.

[ 1March 20, 1973 DIFFUSION TRANSFER RECEPTION ELEMENTS, FILM UNITS ANDPROCESSES THEREFOR lnventors: Richard W. Becker; Glen M. Dappen, both ofRochester, N .Y.

Eastman Kodak Rochester, NY.

Filed: Aug. 24, 1971 Appl. No.: 174,505

Assignee: Company,

US. Cl. ..96/29 D, 96/3, 96/76 C,

96/77, 96/84 R Int. Cl ..G03c 7/00, G03c 5/54, G03c 1/40 Field of Search..96/3, 29 D, 84 R Primary Examiner-J. Travis Brown AssistantExaminerAlfons0 Suro Pico Attorney-Robert W. Hampton et al.

[ 5 7 ABSTRACT Vinyl polymers containing anionic solubilizing groups areemployed as the binder in a light-reflective layer which is associatedwith a dye image-receiving layer employed in color diffusion transfersystems.

22 Claims, No Drawings DIFFUSION TRANSFER RECEPTION ELEMENTS, FILM UNITSAND PROCESSES THEREFOR This invention relates to the art of photographyand more particularly to color diffusion transfer film units, receptionelements and methods for obtaining stable, positive, right-readingdiffusion transfer dye images of high quality.

US. Pat. No. 3,227,550 of Whitmore and Mader issued Jan. 4, i966 andU.S. Pat. No. 3,227,552 of Whitmore issued Jan. 4, 1966 describephotographic image transfer processes wherein an immobile coupler isreacted with oxidized color developer to form a mobile dye which istransferred by diffusion to a receiving layer to form a color image.During the development phase of the color development diffusion transferprocess, the image dyes formed in the respective blue, green andred-sensitive silver halide emulsion layers diffuse into animage-receiving layer of the receiving element where the dyes aremordanted to form the transferred image. At the same time, small amountsof development reaction products and unused color developer diffuse intothe image-receiving layer. When the receiving element is separated fromthe photosensitive element, oxygen in the atmosphere causes rapidoxidation of the unused developer, self-coupling of the developeroccurs, thereby producing a yellowishbrown stain, particularly in thehighlight or minimum density areas.

U.S. Pat. No. 3,445,228 issued May 20, 1969 of Beavers et al. disclosesthat a white pigment contained in an interlayer of a dye image-receivingelement for use in the above-described process conceals the stain formedin an acid layer and functions also as a timing layer. Specific bindersmentioned include gelatin, polyvinyl alcohol and other vinyl polymers.It would be desirable to provide an image-receiving element whereinhigher maximum dye densities are obtainable both initially and afterincubation.

- Accordingly, it is an object of this invention to provide a film unitemploying an image-receiving element capable of receiving stable dyeimages of high quality and process of using same.

It is another object of this invention to provide an image-receivingelement providing higher maximum dye densities of the transferred image,both initially and after subjecting to various atmospheric conditionsfor extended periods of time.

It is another object of this invention to provide a film unit employingan image-receiving element having an increased rate of dye diffusiontransfer in comparison to the prior art.

These and other objects are achieved by a photographic film unitaccording to our invention, which is adapted to be processed by passingthe unit between a pair of juxtaposed pressure'applying members, such aswould be found in a camera designed for in-camera processing,comprising:

a. a photosensitive element comprising a support having thereon at leastone, and preferably three, photosensitive silver halide emulsion layers,each silver halide emulsion layer having associated therewith a dyeimage-providing material;

b. a dye image-receiving layer having a light-reflecting layerassociated therewith comprising a vinyl polymer containing anionicsolubilizing groups and an opacifying agent; and

c. a rupturable container containing an alkaline processing compositionand which is adapted to be positioned during processing of the film unitso that a compressive force applied to the container bypressure-applying members in a camera will effect a discharge of thecontainers contents within the film unit.

Our invention can be used not only in diffusion transfer systems whereinthe image-receiving element is located on a separate support from thephotosensitive element, but also in diffusion transfer systems whereinthe image-receiving element is integral with the photosensitive element.

In one embodiment of our invention wherein the image-receiving elementis separate from the photosensitive element, the novel dyeimage-receiving element comprises a support having thereon the followinglayers:

a. a light-reflecting layer comprising a vinyl polymer containinganionic solubilizing groups and an opacifying agent, and

b. a dye image-receiving layer.

The above-described dye image-receiving element of the film unit isadapted to be superposed on the photosensitive element after exposurethereof. The development and transfer operations can be effected bybathing either or both the exposed photosensitive element and the dyeimage-receiving element in a developing solution before rolling intocontact with each other, or a viscous developing composition can beplaced between the elements for spreading in a predetermined amountacross and into contact with the exposed surface of the photosensitiveelement. The viscous developing composition is desirably utilized in oneor more pods attached to the reception sheet or photosensitive elementthat can be readily ruptured when development is desired as described,for example, in U.S. Pats. Nos. 2,559,643; 2,647,049; 2,661,293;2,698,244; 2,698,798 and 2,774,668.

During the development phase of a color diffusion transfer processaccording to out invention, the dye image-providing material formed inthe respective blue-, greenand red-sensitive silver halide emulsionlayers diffuse out of the photosensitive element through the viscousdeveloper composition and into the dye image-receiving layer, e.g., intothe dye image-receiving element described above, where the dyes aremordanted to form the transferred image.

In another embodiment of our invention, the dye image-receiving layer islocated integral with the photosensitive element between the support andthe lowermost photosensitive silver halide emulsion layer. Such integralreceiver-negative photosensitive elements are described in copendingU.S. application Ser. No. 115,459 of Barr, Bush and Thomas filed Feb.16, 1971 and now abandoned. In such an embodiment, the support for thephotosensitive element is transparent and is coated with the dyeimage-receiving layer, the light-reflective layer described above andthe various layers forming the color-forming units. After exposure ofthe photosensitive element, a rupturable container containing analkaline processing composition and an opaque process sheet are broughtinto superposed position. Pressure-applying members in a camera rupturethe container and spread processing composition over the photosensitiveelement as the film unit is withdrawn from the camera. The processingcomposition develops the exposed silver halide layers and dye images areformed as a function of development which diffuse to the image-receivinglayer to provide a positive, rightreading image which is viewed throughthe transparent support on the opaque reflecting layer background. Forfurther details concerning this particular film unit, its preparationand use, reference is made to the abovementioned U.S. application Ser.No. 115,459 of Barr, Bush andThomas filed Feb. 16, 1971.

Another embodiment of integral receiver-negative photosensitive systemsin which our invention can be employed is described in U.S. Ser. No.115,552 of Cole filed Feb. 16, 1971 and now abandoned. In such anembodiment, the support for the color diffusion transfer system istransparent and is coated with the imagereceiving layer, thelight-reflective layer described above and then the various layersforming the colorforming units and a top transparent sheet. A rupturablecontainer containing an alkaline processing composition and an opacifieris positioned adjacent to the top layer and sheet. The film unit isplaced in a camera, exposed through the top transparent sheet and thenpassed between a pair of pressure-applying members in the camera as itis being removed therefrom. The pressure-applying members rupture thecontainer and spread processing composition and opacifier over thenegative portion of the film unit to render it light insensitive. Theprocessing composition develops the exposed silver halide layers and dyeimages are formed as a result of development which diffuse to theimagereceiving layer to provide a positive, right-reading image which isviewed through the transparent support on the opaque reflecting layerbackground. For further details concerning this particular integral filmunit, its preparation and use, reference is made to the abovementionedCole U.S. application Ser. No. 115,552 filed Feb.l6,197l.

Any vinyl polymer containing anionic solubilizing groups such ascarboxyl groups or sulfonic acid groups can be employed in thelight-reflecting layer according to our invention with good results. Incertain embodiments highly preferred polymers are copolymers comprisingrecurring units of acrylic acid, sulfoalkyl acrylate or sulfoalkylmethacrylate with the remaining units of these copolymers derived fromother ethylenically unsaturated monomers such as, for example, allrylacrylates, alkyl methacrylates, etc. For further details concerningthese polymers and their preparation, reference is made to U.S. Pat. No.3,411,911 of Dykstra issued Nov. 19, 1968; U.S. Pat. No. 3,411,912 ofDylgjstra et al. issued Nov. 19, 1968; U.S. Pat. No. 3,488,708 of Smithissued Jan. 6, 1970; and U.S. Pat. No. 3,220,844 of Hanoi: et al. issuedNov. 30, 1965. Examples of these preferred polymers includecopoly(ethylacrylate, acrylic acid, 2-acetoacetoxyethyl methacrylate),copoly(ethylacrylate, acrylic acid) and copoly(n-butyl acrylate,3-acryloxypropane-l-sulfonic acid sodium salt, Z-acetoacetoxy ethylmethacrylate);

The film assembly of our invention can be used to produce positiveimages in single or multicolors. In a three-color system, each silverhalide emulsion layer of the film assembly of our invention will haveassociated therewith a dye image-providing material possessing aspectral absorption range substantially complementary to the predominantsensitivity range of its associated emulsion, i.e., the blue-sensitivesilver halide emulsion layer will have a yellow dye image-providingmaterial associated therewith, the green-sensitive silver halideemulsion layer will have a magenta dye image-providing materialassociated therewith, and the red-sensitive silver halide emulsion layerwill have a cyan dye imageproviding material associated therewith. Thedye image-providing material associated with each silver halide emulsionlayer can be contained either in the silver halide emulsion layer itselfor in a layer contiguous to the silver halide emulsion layer.

Spectral sensitizing dyes can be used conveniently to confer additionalsensitivity to the light sensitive silver halide emulsion of themultilayer photographic elements of the invention. For instance,additional spectral sensitization can be obtained by treating theemulsion with a solution of a sensitizing dye in an organic solvent orthe dye may be added in the form of a disper sion as described in Owenset al. British Pat. No. 1,154,781 issued June 11, 1969. For optimumresults, the dye can either be added to the emulsion as a final step orat some earlier stage.

Sensitizing dyes useful in sensitizing such emulsions are described, forexample, in Brooker et al., U.S. Pat. No. 2,526,632, issued Oct. 24,1950; Sprague U.S. Pat. No. 2,503,776, issued Apr. 11, 1950; Brooker eta1. U.S. Pat. No. 2.493,748,.issued Jan. 10, 1950; and Taber et al.,U.S. Pat. No. 3,384,486 issued May 21, 1968. Spectral sensitizers whichcan be used include the cyanines, merocyanines, complex (tri ortetranuclear) merocyanines, complex (tri or tetranuclear) cyanines,holopolar cyanines, styryls, hemicyanines, (e.g,, enamine hemicyanines),oxonols and hemioxonols. Dyes of the cyanine classes can contain suchbasic nuclei as the thiazolines, oxazolines, pyrrolines, pyridines,oxazoles, thiazoles, selenazoles and imidazoles. Such nuclei can containalkyl, alkylene, hydroxyalkyl, sulfoalkyl, aminoalkyl and enamine groupsand can be fused to carbocyclic or heterocyclic ring systems eitherunsubstituted or substituted with halogen, phenyl, alkyl, haloalkyl,cyano, or alkoxy groups. The dyes can be symmetrical or unsymmetricaland can contain alkyl, phenyl, enamine or heterocyclic substituents onthe methine or polymethine chain. The merocyanine dyes can contain thebasic nuclei mentioned above as well as acid nuclei such asthiohydantoins, rhodanines, oxazolidenediones, thiazolidenediones,barbituric acids, thiazolineones, and malononitrile. These acid nucleican be substituted with alkyl, alkylene, phenyl, carboxyalkyl,sulfoalkyl, hydroxyallryl, alkoxyalkyl, alkylamino groups, orheterocyclic nuclei. Combinations of these dyes can be used, if desired.In addition, supersensitizing addenda which do not absorb visible lightcan be included, for instance, ascorbic acid derivatives, azaindenes,cadmium salts, and organic sulfonic acids as described in McFall et a1.U.S. Pat. No. 2,933,390 issued Apr. 19, 1960 and Jones et a1. U.S. Pat.No. 2,937,089 issued May 17, 1960.

The various silver halide emulsion layers of a color film assembly ofthe invention can be disposed in the usual order, i.e., theblue-sensitive silver halide emulsion layer first with respect to theexposure side, followed by the green-sensitive and red-sensitivesilverhacarboxyalkyl,

lide emulsion layers. If desired, a yellow dye layer or a Carey Leasilver layer can be present between the bluesensitive andgreen-sensitive silver halide emulsion layer for absorbing or filter-ingblue radiation that may be transmitted through the blue-sensitive layer.If desired, the selectively sensitized silver halide emulsion layers canbe disposed in a different order, e.g., the blue-sensitive layer firstwith respect to the exposure side, followed by the red-sensitive andgreen-sensitive layers.

The silver halide emulsions used in this invention can comprise, forexample, silver chloride, silver bromide, silver chlorobromide, silverbromoiodide, silver chlorobromoiodide or mixtures thereof. The emulsionscan be coarse or fine grain and can be prepared by any of the well-knownprocedures, e.g., single jet emulsions such as those described inTrivelli and Smith, The Photographic Journal, Vol. LXXIX, May, 1939 (pp330-338), double jet emulsions, such as Lippmann emulsions, ammoniacalemulsions, thiocyanate or thioether ripened emulsions such as thosedescribed in Nietz et al. U.S. Pat. No. 2,222,264 issued Nov. 19, 1940;Illingsworth U.S. Pat. No. 3,320,069 issued May 16, 1967; and McBrideU.S. Pat. No. 3,271,157 issued Sept. 6, 1966. Surface image emulsionscan be used or internal image emulsions can be used such as thosedescribed in Davey et al U.S. Pat. No. 2,592,250 issued May 8, 1952;Porter et al. U.S. Pat. No. 3,206,313 issued Sept. 14, 1965; BerrimanU.S. Pat. No. 3,367,778 issued Feb. 6, 1968; and Bacon et al. U.S. Pat.No. 3,447,927 issued June 3, 1969. The emulsions may be regular grainemulsions such as the type described in Klein and Moisar, J. Phot. Sci.,Vol. 12, No. 5, Sept./Oct., 1964, (pp. 242-251). Negative type emulsionsmay be used or direct positive emulsions may be used such as thosedescribed in Leermakers U.S. Pat. No. 2,184,013 issued Dec. 19, 1939;Kendall et al. U.S. Pat. No. 2,541,472 issued Feb. 13, 1951; BerrimanU.S. Pat. No. 3,367,778 issued Feb. 6, 1968; Schouwenaars British Pat.No. 723,019 issued Feb. 2, 1955; lllingsworth et al. French Pat. No.1,520,821 issued Mar. 4, 1968; Illingsworth U.S. Pat. No. 3,501,307issued Mar. 17, 1970; Ives U.S. Pat. No. 2,563,785 issued Aug. 7, 1951;Knott et al. U.S. Pat. No. 2,456,953 issued Dec. 21, 1948; and Land U.S.Pat. No. 2,861,885 issued Nov.25, 1958.

The emulsions used with this invention may be sensitized with chemicalsensitizers, such as with reducing agents; sulfur, selenium or telluriumcompounds; gold, platinum or palladium compounds; or combinations ofthese. Suitable procedures are described in Sheppard et al. U.S. Pat.No. 1,623,499 issued Apr. 5, 1927; Waller et al. U.S. Pat. No. 2,399,083issued Apr. 23, 1946; McVeigh U.S. Pat. No. 3,297,447 issued Jan. 10,1967; and Dunn U.S. Pat. No. 3,297,446 issued Jan. 10, 1967.

The silver halide emulsions used with this invention may contain speedincreasing compounds such as polyalkylene glycols, cationic surfaceactive agents and thioethers or combinations of these as described inPiper U.S. Pat. No. 2,886,437 issued May 12, 1959; Dann et al. U.S. Pat.No. 3,046,134 issued July 24, 1962; Carroll et al. U.S. Pat. No.2,944,900 issued July 12, 1960; and Goffe U.S. Pat. No. 3,294,540 issuedDec. 27, 1966.

The silver halide emulsions used in the practice of this invention canbe protected against the production of fog and can be stabilized againstloss of sensitivity during keeping. Suitable antifoggants andstabilizers each used alone or in combination include thiazolium saltsdescribed in Brooker et al. U.S. Pat. 2,131,038 issued Sept. 27, 1938;and Allen et al. U.S. Pat. No. 2,694,716 issued Nov. 16, 1954; theazaindenes described in Piper U.S. Pat. No. 2,8 86,437 issued May 12,1959; and l-leimbach et al. U.S. Pat. No. 2,444,605 issued July 6, 1948;the mercury salts as described in Allen et al. U.S. Pat. No. 2,728,663issued Dec. 27, 1955; the urazoles described in Anderson et al U.S. Pat.No. 3,287,135 issued Nov. 22, 1966; the sulfocatechols described inKennard et al. U.S. Pat. No. 3,236,652 issued Feb. 22, 1966; the oximesdescribed in Carroll et al. British Pat. No. 623,448 issued May 18,1949; nitrogen; nitroindazoles; the mercaptotetrazoles described inKendall et al. U.S. Pat. No. 2,403,927 issued July 16, 1946; Kennard etal. U.S. Pat. No. 3,266,897 issued Aug. 16, 1966; and Luckey et al. U.S.Pat. No. 3,397,987 issued Aug. 20, 1968; the polyvalent metal saltsdescribed in Jones U.S. Pat. No. 2,839,405 issued June 17, 1958; thethiuronium salts described in Herz et al. U.S. Pat. No. 3,220,839 issuedNov. 30, 1965; the palladium, platinum and gold salts described inTrivelli et al. U.S. Pat. No. 2,566,263 issued Aug. 28, 1951; and Yutzyet al U.S. Pat. No. 2,597,915 issued May 27, 1952; and the tetrazolesdescribed in Hoppe U.S. Pat. No. 3,352,672 issued Nov. 14,1967.

Any dye image-providing material can be employed in this invention aslong as an imagewise distribution of the material will be formed afterdevelopment as a function of the imagewise exposure of the silver halideemulsion to which the dye image-providing material is associated. Forexample, there may be employed as the dye image-providing material dyedevelopers as illustrated by U.S. Pat. No. 2,983,606; coupling dyes asdisclosed, for example, in U.S. Pat. No. 3,087,817; shifted or leuco dyedevelopers; dye developer precursors; metal dye complexes as disclosed,for example, in U.S. Pats. Nos. 3,185,567 and 3,453,107; couplersrequiring an oxidizing agent in the image-receiving layer to form acolor; ring-closing dye developers as disclosed in U.S. Pat. No.3,443,943; color-providing materials as disclosed in U.S. Pats. Nos.3,443,940 and 3,443,941; etc.

Particularly good results are obtained in this invention when the dyeimage-providing material associated with each silver halide emulsionlayer is a nondiffusible coupler which produces a diffusible dye uponreaction with oxidized aromatic primary amino color developing agents,such as p-phenylenediamine developing agents. Such couplers includethose having the formulas:

DYE LINK (COUP BALL) and BALL LINK (COUP SOL) wherein l. DYE is a dyeradical exhibiting selective absorption in the visible spectrum andcontaining an acidic solubilizing radical;

No. I

. LINK is a connecting radical such as an azo radical, a mercuriradical, an oxy radical, an alkylidene radical, a thio radical, a dithioradical or an azoxy radical;

3. COUP is a coupler radical such as a S-pyrazolone coupler radical, apyrazolotriazole coupler radical, a phenolic coupler radical or anopen-chain ketomethylene coupler radical, COUP being substituted in thecoupling position with LINK;

. BALL is a photographically inert organic ballasting radical ofsuchmolecular size and configuration as to render such coupler nondiffusibleduring development in the alkaline processing composition;

5. SOL is a hydrogen atom or an acidic solubilizing group when the colordeveloping agent contains an acidic solubilizing group, and SOL is anacidic solubilizing group when the color developing agent is free of anacidic solubilizing group; and

. n is an integer of l to 2 when LINK is an alkylidene radical, and n is1 when LINK is an azo radical, a mercuri radical, an oxy radical, a thioradical, a dithio radical or an azoxy radical.

For further details concerning the above-described couplers, theirpreparation and use, reference is made to U.S. Pat. No. 3,227,550 ofWhitmore et al. issued Jan. 4, 1966; U.S. Pat. No. 3,227,552 of Whitmoreissued Jan. 4, 1966; and British Pat. No. 904,364, page 19, lines 1-41.

If the silver halide emulsion employed with the nondiffusible couplersdescribed above is a direct positive silver halide emulsion, such as aninternal image emulsionor a solarizing emulsion, which is developable inunexposed areas, a positive image can be obtained on the dyeimage-receiving layer. In this embodiment, the nondiffusible coupler canbe located in the silver halide emulsion itself. After exposure of thefilm unit, the alkaline processing composition permeates the variouslayers to initiate development of the exposed photosensitive silverhalide emulsion layers. The aromatic primary amino color developingagent present in the film unit develops each of the silver halideemulsion layers in the unexposed areas (since the silver halideemulsions are direct positive ones), thus causing the developing agentto become oxidized imagewise corresponding to the unexposed areas of thedirect positive silver halide emulsion layers. The oxidized developingagent then reacts with the nondiffusible coupler present in each silverhalide emulsion layer to form imagewise distributions, respectively, ofdiffusible cyan, magenta and yellow dye as a function of the imagewiseexposure of each of the silver halide emulsion layers. At least aportionof the imagewise distributions ofdiffusible cyan, magenta and yellow dyediffuse to the image-receiving layer to provide a positive dye imageupon separation of the receiver from the negative.

Internal image silver halide emulsions useful in the above-describedembodiment are direct positive emulsions that form latent imagespredominantly inside the silver halide grains, as distinguished fromsilver halide grains that form latent images predominantly on thesurface thereof. Such internal image emulsions were described by Daveyet al. in US. Pat. No. 2,592,250 issued Apr. 8, 1952, and elsewhere inthe literature.

These emulsions can also contain fogging or nucleating agents such asthose described in U.S. Pats. Nos. 2,588,982; 2,563,785; 3,227,552; etc.

As previously mentioned, the aromatic primary amino color developingagent employed in the abovedescribed embodiment is preferably present inthe alkaline processing composition in the rupturable pod. The colordeveloping agent can also be incorporated into the negative portion ofthe film unit as a separate layer, e.g., by employing a Schiff basederivative of an aromatic primary amino color developing agent such asthat formed by reacting o-sulfobenzaldehyde and N,N-diethyl-3-methyl-4-aminoaniline. Such incorporated developing agent willbe activated by the alkaline processing composition. While theincorporated developing agent can be positioned in any layer of thephotosensitive element from which it can be readily made available fordevelopment upon activation with alkaline processing composition, it isgenerally either incorporated in the light-sensitive silver halideemulsion layers or in layers contiguous thereto. As mentioned above,aromatic primary amino color developing agents employed in certainembodiments of this invention are preferably p-phenylenediaminedeveloping agents. These developing agents are well known to thoseskilled in the art and include the following compounds and saltsthereof: 4-amino-N,N-diethyl-3- methyl aniline,N,N-diethyl-p-phenylenediamine, N-ethyl-B-methane-sulfonamido-ethyl-3-methyl-4- aminoaniline,4-amino-N-ethyl-3-methyl-N-B-sulfoethyl)aniline,4-amino-N-ethyl-3-methoxy-N-(B-sulfoethyl)aniline,4-amino-N-ethyl-N-(B-hydroxyethyl)aniline,4-amino-N,N-diethyl-3-hydroxymethyl aniline,4-amino-N-methyl-N-(B-carboxyethyl)aniline,4-amino-N,N-bis-(B-hydroxyethyl)aniline, 4-amino-N,N-bis(fi-hydroxyethyl)-3-methyl aniline, 3-acetamido-4-amino-N,N-bis(B-hydroxyethyl)-aniline,4-amino-N-ethyl-N-(2,3-dihydroxypropyl)-3-methyl aniline,4-amino-N,N-diethyl-3-(3-hydroxypropoxy)aniline, and the like.

In a color film unit according to the invention, each silver halideemulsion layer containing a dye imageproviding material or having thedye image-providing material present in a contiguous layer may beseparated from the other silver halide emulsion layers in the negativeportion of the film unit by materials in addition to those describedabove, including gelatin, calcium alginate, or any of those disclosed inU.S. Pat. No. 3,384,483, polymeric materials such as polyvinylamides asdisclosed in U.S. Pat. No. 3,421 ,892,or any of those disclosed in U.S.Pats. Nos. 2,992,104; 3,043,692; 3,044,873; 3,061,428; 3,069,263;3,069,264; 3,l21,0ll;and 3,427,158.

Generally speaking, except where noted otherwise, the silver halideemulsion layers in the invention comprise photosensitive silver halidedispersed in gelatin and are about 0.6 to 6 microns in thickness; thedye image-providing materials are dispersed in an aqueous alkalinesolution-permeable polymeric binder, such as gelatin, as a separatelayer about 1 to 7 microns in thickness; and the alkalinesolution-permeable polymeric interlayers, e.g., gelatin, are about 1 to5 microns in thickness. Of course, these thicknesses are approximateonly and can be modified according to the product desired. In additionto gelatin, other suitable hydrophilic materials include bothnaturally-occurring substances such as proteins, cellulose derivatives,polysaccharides such as dextran, gum arabic and the like; and syntheticpolymeric substances such as water soluble polyvinyl compounds likepoly(vinylpyrrolidone), acrylamide polymers and the like.

The photographic emulsion layers and other layers of a photographicelement employed in the practice of this invention can also containalone or in combination with hydrophilic, water-permeable colloids,other synthetic polymeric compounds such as dispersed vinyl compoundssuch asin latex form and particularly those which increase thedimensionl stability of the photographic materials. Suitable syntheticpolymers include those described, for example, in Nottorf U.S. Pat. No.3,142,568, issued July 28, 1964; White U.S. Pat. No. 3,193,386, issuedJuly 6,1965; Houck et al. U.S. pat. No. 3,062,674, issued Nov. 6, 1962;Houck et al. U.S. Pat. No. 3,220,844, issued Nov. 30, 1965; Ream et al.U.S. Pat. No. 3,287,289, issued Nov. 22, 1966; and Dykstra U.S. Pat. No.3,411,911, issued Nov. 19, 1968. Particularly effective arewater-insoluble polymers of alkyl acrylates and methacrylates, acrylicacid, sulfoalkyl acrylates or methacrylates, those which havecrosslinking sites which facilitate hardening or curing described inSmith U.S. Pat. No. 3,488,708 issued Jan. 6, 1970, and those havingrecurring sulfobetaine units as described in Dykstra Canadian Pat. No.774,054.

Any material can be employed as the image-receiving layer in thisinvention as long as the desired func tion of mordanting or otherwisefixing the dye images will be obtained. The particular material chosenwill, of course, depend upon the dye to be mordanted. lf acid dyes areto be mordanted, the image-receiving layer can contain basic polymericmordants such as polymers of amino guanidine derivatives of vinyl methylketone such as described in Minsk U.S. Pat. No. 2,882,156 issued Apr.14, 1959, and basic polymeric mordants such as described in copendingU.S. Application Ser. No. 100,491. of Cohen et al. filed Dec. 21, 1970and now abandoned. Other mordants useful in our invention includepoly4-vinylpyridine, the 2-vinyl pyridine polymer metho-p-toluenesulfonate and similar compounds described in Sprague et al. U.S. Pat.No. 2,484,430 issued Oct. 1 1, 1949, and cetyl trimethylammoniumbromide, etc. Effective mordanting compositions are also described inWhitmore U.S. Pat. No. 3,271,148 andv Bush U.S. Pat. No. 3,271,147, bothissued Sept. 6, 1966.

Furthermore, the image-receiving layer can be sufficient by itself tomordant the dye as in the case of use of an alkaline solution-permeablepolymeric layer such as N-methoxy methyl polyhex ylmethylene adipamide;partially hydrolyzed polyvinyl acetate; polyvinyl alcohol with orwithout plasticizers; cellulose acetate; gelatin; and other materials ofa similar nature. Generally, good results are obtained when theimagereceiving layer, preferably alkaline solutionpermeable, istransparent and about 0.25 to about 0.04 mil in thickness. Thisthickness, of course, can be modified depending upon the result desired.The image-receiving layer can also contain ultra-violet absorbingmaterials to protect the mordanted dye images from fading due toultraviolet light, brightening agents such as the stilbenes, coumarins,triazines, oxazoles,

dye stabilizers such as the chromanols, alkylphenols, etc.

Use of a pH-lowering material associated with the dye image-receivingelement of the invention will usually increase the stability of thetransferred image. Generally, the pH-lowering material will effect areduction in the pH of the image layer from about 13 or 14 to at least 1l and preferably 5-8 within a short time after imbibition. For example,polymeric acids as disclosed in U.S. Pat. No. 3,362,819; or metallicsalts, e.g., zinc acetate, zinc sulfate, magnesium acetate, theformates, acetates, propionates, stearates, nitrates, or sulfates ofzinc, aluminum, iron, manganese, cobalt of nickel, etc.; or solid acidsas disclosed in U.S. Pat. No. 2,584,030 may be employed with goodresults. Such pH-lowering materials reduce the pH of the film unit afterdevelopment to terminate development and substantially reduce furtherdye transfer and thus stabilize the dye image. The pH-lowering materialcan be present as a separate layer between the light-reflecting layerand its support where the image-receiving element is separate from thephotosensitive element or can be located between the light-reflectinglayer and the lowermost silver halide emulsion layer in an integralreceivernegative element.

Any opacifying agent can be employed in the lightreflecting layeraccording to our invention. Particularly desirable are white opacifyingagents since they would provide an esthetically pleasing background onwhich to view a transferred dye image and would possess the opticalproperties desired for reflection of incident radiation. Suitableopacifying agents include: titanium dioxide, barium sulfate, zinc oxide,barium stearate, silver flake, silicates, alumina, zirconium oxide,zirconium acetyl acetate, sodium zirconium sulfate, kaolin, mica, ormixtures thereof in widely varying amounts depending upon the degree ofopacity desired. Especially good results are obtained with titaniumdioxide. Zinc oxide in combination with titanium dioxide may also beemployed to great advantage as disclosed and claimed in copendingapplication Ser. No. 174,443 of Abbott, Dappen and lrani filed of evendate herewith. Brightening agents such as the stilbenes, coumarins,triazines and oxazoles can also be added to the opacifying layer ifdesired. It is believed that any stain resulting from excess developingagent or oxidized developing agent is hidden in or masked by this layer.

Where a pH-lowering layer is employed, such as a polymeric acid layer,the vinyl polymer containing anionic solubilizing groups in theopacifying layer will function as a timing" layer and will control thepH reduction of the dye image-receiving element as a function of therate at which the alkali diffuses through the layer. Of course,widelyvarying amounts of the vinyl polymer containing anionicsolubilizing groups can be employed in the opacifying layer, dependingupon the results desired.

The alkaline processing composition employed in this invention is theconventional aqueous solution of an alkaline material, e.g., sodiumhydroxide, sodium carbonate or an amine such as diethylamine, preferablypossessing a pH in excess of 12. The solution also preferably contains aviscosity-increasing compound such as a high molecular weight polymer,e.g., a watersoluble ether inert to alkaline solutions such ashydroxyethyl cellulose or alkali metal salts of carboxymethyl cellulosesuch as sodium carboxymethyl cellulose. A concentration ofviscosity-increasing compound of about 1 to about 5 percent by weight ofthe processing solution is preferred which will impart thereto aviscosity of about 100 cps. to about 200,000 cps.

While the alkaline processing composition used in this invention can beemployed in a rupturable container, as described previously, othermethods of applying processing composition could also be employed, e.g.,bathing the photosensitive element in a processing bath, interjectingprocessing composition with communicating members similar to hypodermicsyringes which are attached either to a camera or camera cartridge,

etc.

While the film units of our invention can be modified so as to beemployed in roll form, they are preferably used in cartridges similar tothose described in U.S. Pat. Nos. 3,080,805; 3,161,118; and 3,161,122;said patents 7 also illustrating typical cameras for performing colordiffusion transfer processes of our invention.

The supports for the photographic elements of this invention can be anymaterial as long as it does not deleteriously effect the photographicproperties of the film unit and is dimensionally stable. Typicalmaterials include cellulose nitrate film, cellulose acetate film,po1y(vinyl acetal) film, polystyrene film, poly(ethyleneterephthalate)film, polycarbonate film, poly-a-olefins such as polyethylene andpolypropylene film, and related films or resinuous materials as well asglass, paper, metal, etc. The support is usually about 2 to 6 mils inthickness.

While the invention has been described with reference to layers ofsilver halide emulsions and dye image-providing materials, dotwisecoating, such as would be obtained using a gravure printing technique,could also be employed. In this technique, small dots of blue, green andred-sensitive emulsions have associated therewith, respectively, dots ofyellow, magenta and cyan color-providing substances. After development,the transferred dyes would tend to fuse together into a continuous tone.

The photographic layers employed in the practice of this invention maycontain surfactants such as saponin; anionic compounds such as the alkylaryl sulfonates described in Baldsiefen U.S. Pat. No. 2,600,831 issuedJune 17, 1952; amphoteric compounds such as those described in Ben-EzraU.S. Pat. No. 3,133,816 issued May 19, 1964; and water soluble adductsof glycidol and an alkyl phenol such as those described in OlinMathieson British Pat. No. 1,022,878 issued Mar. 16, 1966; and Knox U.S.Pat. No. 3,514,293 issued May 26, 1970.

The various layers, including the photographic layers, employed in thepractice of this invention can contain light absorbing materials andfilter dyes such as those described in Sawdey U.S. Pat. No. 3,253,921issued May 31, 1966; Gaspar U.S. Pat. No. 2,274,782 issued Mar. 3, 1942;Silberstein et al. U.S. Pat. No. 2,527,583 issued Oct. 31, 1950; andVanCampen U.S. Pat. No. 2,956,879 issued Oct. 18,1960.

The sensitizing dyes and other addenda used in the 65 practice of thisinvention can be added from water solutions or suitable organic solventsolutions may be used. The compounds can be added during variousprocedures including those described in Collins et a1. U.S. Pat. No.2,912,343 issued Nov. 10, 1959; McCrossen et al. U.S. Pat. No. 3,342,605issued Sept. 19, 1967; Audran U.S. Pat. No. 2,996,287 issued Aug. 15,1961 and Johnson et a1. U.S. Pat. No. 3,425,835 issued Feb. 4, 1969.

The photographic layers used in the practice of this invention may becoated by various coating procedures including dip coating, air knifecoating, curtain coating, or extrusion coating using hoppers of the typedescribed in Beguin U.S. Pat. No. 2,681,294 issued June 15, 1954. Ifdesired, two or more layers may be coated simultaneously by theprocedures described in Russell U.S. Pat. No. 2,761,791 issued Sept. 4,1956; Hughes U.S. Pat. No. 3,508,947 issued Apr. 28, 1970; and WynnBritish Pat. No. 837,095 issued June 9, 1960. This invention also can beused for silver halide layers coated by vacuum evaporation as describedin British Pat. No. 968,453 issued Sept. 2, 1964 and Lu- Valle et a1.U.S. Pat. No. 3,219,451 issued Nov. 23, 1965.

The photographic and other hardenable layers used in the practice ofthis invention can be hardened by various organic or inorganichardeners,'alone or in combination, such as the aldehydes, and blockedaldehydes as described in Allen et a1. U.S. Pat. No. 3,232,764 issuedFeb. 1, 1966; ketones, carboxylic and carbonic acid derivatives,sulfonate esters, sulfonyl halides and vinyl sulfonyl ethers asdescribed in Burness et al. U.S. Pat. No. 3,539,644 issued Nov. 10,1970; active halogen compounds, epoxy compounds, aziridines, activeolefins, isocyanates, carbodiimides, polymeric hardeners such asoxidized polysaccharides like dialdehyde starch and oxyguargum and thelike.

The following examples further illustrate the invention.

EXAMPLE 1 Dye image-receiving elements are prepared by coating thefollowing layers in the order recited on a transparent cellulose acetatefilm support:

1.- Mordant layer of methyl-tri-n-dodecylammonium p-toluenesulfonate (22mg/ft), N-n-hexadecyl-nmorpholinium ethosulfate (150 mg/ft) and gelatin(650 mg/ft),

2. lnterlayer of gelatin (100 mg.ft'), and

3. Light-reflecting layer of titanium dioxide (3000 mg/ft) and thecompounds identified in Table 1 50 below (300 mg/ft) A photographicelement is prepared by coating the following layers in the order recitedon a transparent support:

1. Gelatin (454 mg/ft),

2. Gelatin-silver bromoiodide emulsion (300 mg of gelatin/ft and 100 mg.of silver/ft) and magenta dye image transfer couplerl-phenyl-3-(3,5-disulfobenzamido)-4-(6-hydroxy-4-pentadecylphenylazo)-5-pyrazolone,dipotassium salt (75 mg/ft'), and

3. Overcoat of gelatin'( 100 mg/ft') Samples of the above photosensitiveelement are flash exposed. The following processing composition isspread from a pod between the exposed surface of the elements and thesuperposed image-receiving elements by passing the transfer sandwichbetween a pair of juxtaposed pressure rollers:

4-amino-3-methoxy-N-ethyl-N-B- hydroxyethylanilino hydrochloride 3sodium thiosulfate piperidino hexose reductone hydroxyethyl cellulosesodium hydroxide water to The dye diffusion transfer time in seconds isobserved for the first appearance of magenta dye in the dyeimage-receiving layer. After 60 seconds at about 20C., the dyeimage-receiving element is peeled apart from the negative and the greenreflection densities for both fresh and incubated coatings are measured.The following results are obtained:

TABLE 1 First AD max. AD max. Polymer in Lightappea Fresh 1 wk.at 5wks.at Reflecting Layer rance D max.49C/50%RH 20C/S0%RH of dye (sec.)

Gelatin (control) 14 1.24 0.ll 0.42 Poly(vinyl alcohol) (control) 111.48 0.l0 0.35 Copoly(ethylacrylate,

acrylic acid, 2-acetoacetoxyethyl methacrylate) (7l.8:23.8:4.4 byweight) 10 1.35 0.01 0.01 Copoly(ethylacrylate, acrylic acid) (80:20 byweight) 10 1.31 0.05 0.05

The above results indicate the higher Dmax. which can be obtained inaccordance with our invention in comparison with one of the materials ofthe prior art along with the enhanced keeping stability and theincreased rate of dye diffusion transfer in comparison with bothmaterials of the prior art.

EXAMPLE 2 Dye image-receiving elements are prepared similar to those ofExample 1 except that layer 3 contains titanium dioxide (2,500 mg/ft andthe compounds identified in Table 11 below (125 mg/ft These dyeimage-receiving elements are then tested in accordance with theprocedure described in Example 1 to give the following results:

TABLE ll First Polymer in Lightappearance fresh Reflecting Layer of dye(see) dmax. Gelatin 40 1.04 Copoly(n-butyl acrylate,3-acryloxy-propanel-lull'onic acid sodium salt, Z-acetoacetoxy ethylmethacrylate) (90.2:5.8:4 by weight) 18 1.65 Copoly(ethylscrylste,acrylic ncid,'2-

acetoacetoxycthyl methacrylate) (71.8:23.8:4.4 by weight) 14 2.00

The above results again indicate the higher Dmax. and increased rate ofdye diffusion transfer which can be obtained in accordance with ourinvention in comparison with a prior art material.

The invention has been described in detail with particular reference topreferred embodiments thereof, but, it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

We Claim:

1. In a photographic film unit which is adapted to be processed bypassing said unit between a pair of juxtaposed pressure-applying memberscomprising:

a. a photosensitive element comprising a support having thereon at leastone photosensitive silver halide emulsion layer, each said silver halideemulsion layer having associated therewith a dye image-providingmaterial;

. a dye image-receiving layer having a light-reflecting layer associatedtherewith; and

c. a rupturable container containing an alkaline processing compositionand which is adapted to be positioned during processing of said filmunit so that a compressive force applied to said container by saidpressure-applying members will effect a discharge of the containerscontents within said film unit;

the improvement comprising employing assaid lightreflecting layer avinyl polymer containing anionic solubilizing groups and an opacifyingagent.

2. The photographic film unit of claim 1 wherein said photosensitiveelement comprises a support having thereon a red-sensitive silver halideemulsion layer having associated therewith a cyan dye image-providingmaterial comprising a nondiffusible coupler capable of reacting withoxidized aromatic primary amino color developing agent to produce adiffusible cyan dye, a green-sensitive silver halide emulsion layerhaving associated therewith a magenta dye image-providing materialcomprising a nondiffusible coupler capable of reacting with oxidizedaromatic primary amino color developing agent to produce a diffusiblemagenta dye, and a blue-sensitive silver halide emulsion layer havingassociated therewith a yellow dye image-providing material comprising anondiffusible coupler capable of reacting with oxidized aromatic primaryamino color developing agent to produce a diffusible yellow dye; saidfilm unit containing an aromatic primary amino color developing agent.

3. The film unit of claim 1 wherein said dye imagereceiving layer islocated in said photosensitive element between said support and thelowermost photosensitive silver halide emulsion layer, and saidlight-reflecting layer is located in said photosensitive element betweensaid dye image-receiving layer and said lowermost photosensitive silverhalide emulsion layer.

4. The film unit of claim 1 wherein said dye imagereceiving layer iscoated on a separate support and is adapted to be superposed on saidphotosensitive element after exposure thereof, and said light-reflectinglayer is located between said dye image-receiving layer and its saidsupport.

5. The film unit of claim 4 wherein said rupturable container is sopositioned during processing of said film unit that a compressive forceapplied to said container by said pressure-applying members will effecta discharge of the containers contents between said dye image-receivinglayer and the outermost layer of said photosensitive element.

6. The film unit of claim 1 which also contains a pH- lowering material.

7. The film unit of claim 1 wherein said opacifying agent is titaniumdioxide.

8. The film unit of claim I wherein said vinyl polymer is a copolymercomprising units of acrylic acid, sulfoalkyl acrylate or sulfoalkylmethacrylate.

9. The film unit of claim I wherein said vinyl polymer iscopoly(ethylacrylate, acrylic acid, 2-acetoacetoxyethyl methacrylate),copoly(ethylacrylate, acrylic acid) or copoly(n-butyl acrylate,3-acryloxypropane-lsulfonic acid sodium salt, 2-acetoacetoxy ethylmethacrylate).

10. In a photographic film unit which is adapted to be processed bypassing said unit between a pair of juxtaposed pressure-applying memberscomprising:

l. a photosensitive element comprising a support having thereon thefollowing layers in sequence:

a. a direct-positive, red-sensitive silver halide emulsion layercontaining a nondiffusible coupler capable of reacting with oxidizedaromatic primary amino color developing agent to produce a diffusiblecyan dye;

b. an'alkaline solution-permeable interlayer containing a compoundcapable of scavenging oxidized aromatic primary amino color developingagent;

. a direct-positive, green-sensitive silver halide emulsion layercontaining a nondiffusible coupler capable of reacting with oxidizedaromatic primary amino color developing agent to produce a diffusiblemagenta dye;

. analkaline solution-permeable interlayer containing a compound capableof scavenging ox idized aromatic primary amino color developing agent;and

e. a direct-positive, blue-sensitive silver halide emulsion layercontaining a non-diffusible coupler capable of reacting with oxidizedaromatic primary amino color developing agent to produce a diffusibleyellow dye;

each said nondiffusible coupler having the formula:

DYE LINK coup BALL),

BALL LINK (COUP SOL),

wherein:

l. DYE is a dye radical exhibiting selective absorption in the visiblespectrum and containing an acidic solubilizing group;

2. LINK is a connecting radical selected from the group consisting of anazo radical, a mercuri radical, an oxy radical, an alkylidene radical, athio radical, a dithio radical and an azoxy radical;

3. COUP is a coupler radical selected from the group consisting of aS-pyrazolone coupler radical, a pyrazolotriazole coupler radical, aphenolic coupler radical and an open-chain ketomethylene couplerradical, said COUP being substituted in the coupling position with saidLINK;

. BALL is a photographically inert organic ballasting radical of suchmolecular size and configuration as to render said coupler nondiffusibleduring development in said alkaline processing composition;

5. SOL is selected from the group consisting of a hydrogen atom and anacidic solubilizing group when said color developing agent con-tains anacidic solubilizing group, and SOL is an acidic solubilizing when saidcolor developing agent is free of an acidic solubilizing group; and

. n is an integer of l to 2 when said LINK is an alkylidene radical, andn is 1 when said LINK is a radical selected from the group consisting ofan azo radical, a mercuri radical, an oxy radical, a thio radical, adithio radical and an azoxy radical;

II. a dye image-receiving element comprising a support having thereon adye image-receiving layer, said element being adapted to be superposedover said blue-sensitive silver halide emulsion layer after exposure ofsaid photosensitive element; and

III. a rupturable container containing an alkaline processingcomposition and which is adapted to be positioned during processing ofsaid film unit so that a compressive force applied to said container bysaid pressure-applying members will effect a discharge of the containerscontents between said dye image-receiving layer and said blue-sensitivesilver halide emulsion layer of said photosensitive element;

said film unit containing an aromatic primary amino color developingagent; the improvement comprising employing as said dye image-receivingelement a support having thereon a polymeric acidic material layer, alight-reflecting layer, comprising a vinyl polymer con taining anionicsolubilizing groups and an opacifying agent, and a dye image-receivinglayer.

11. The photographic film unit of claim 10 wherein said vinyl polymer isa copolymer comprising units of acrylic acid, sulfoalkyl acrylate orsulfoalkyl methacrylate and said opacifying agent is titanium dioxide.

12. The photographic film unit of claim 11 wherein said vinyl polymer iscopoly(ethylacrylate, acrylic acid, 2-acetoacetoxyethyl methacrylate),copoly(ethylacrylate, acrylic acid) or copoly(n-butyl acrylate, 3-acryloxypropane-l-sulfonic acid sodium salt, 2- acetoacetoxy ethylmethacrylate).

13. A reception element comprising a support having thereon a. alight-reflecting layer comprising a vinyl polymer containing anionicsolubilizing groups and an opacifying agent, and

b. a dye image-receiving layer.

14. The reception element of claim 13 which includes a pH-lowering layerbetween said support and said layer a.

15. The reception element of claim 13 wherein said opacifying agent istitanium dioxide.

16. The reception element of claim 13 wherein said vinyl polymer is acopolymer comprising units of acrylic acid, sulfoalkyl acrylate orsulfoalkyl methacrylate.

17. The reception element of claim 16 wherein said vinyl polymer iscopoly(ethylacrylate, acrylic acid, 2- acetoacetoxyethyl methacrylate),copoly(ethylacrylate, acrylic acid) or copoly(n-butyl acrylate, 3-acryloxypropane-l-sulfonic acid sodium salt, 2- acetoacetoxy ethylmethacrylate).

18. The reception element of claim 17 wherein said opacifying agent istitanium dioxide. 19. In a process of forming a transfer image'comprisa. imagewise-exposing a photosensitive element comprising a supporthaving thereon at least one photosensitive silver halide emulsion layer,each said silver halide emulsion layer having associated therewith a dyeimage-providing material;

b. treating the layer outermost from the support of said exposedphotosensitive element with an alkaline processing compo-sition toeffect development of each of said exposed silver halide emulsionlayers;

c. forming an imagewise distribution of diffusible dye image-providingmaterial as a function of said imagewise exposure of each said silverhalide emulsion layer; and

d. at least a portion of each said imagewise distribution of diffusibledye image-providing material diffusing to a dye image-receiving layerhaving a light-reflecting layer associated therewith;

the improvement comprising employing as said lightreflecting layer avinyl polymer containing anionic solubilizing groups and an opacifyingagent.

20. The process of claim 19 wherein said treatment step b. is effectedby A. superposing over the layer outermost from theacryloxypropane-l-sulfonic acid sodium 21. The process of claim 20wherein said vinyl polymer is a copolymer comprising units of acrylicacid, sulfoalkyl acrylate or sulfoalkyl methacrylate.

' 22. The process of claim 2] wherein said vinyl polymer iscopoly(ethylacrylate, acrylic acid, 2- acetoacetoxyethyl methacrylate),copoly(ethylacrylate, acrylic acid) or copoly(n-butyl acrylate, 3- salt,2- acetoacetoxy ethyl methacrylate).

2. The photographic film unit of claim 1 wherein said photosensitiveelement comprises a support having thereon a red-sensitive silver halideemulsion layer having associated therewith a cyan dye image-providingmaterial comprising a nondiffusible coupler capable of reacting withoxidized aromatic primary amino color developing agent to produce adiffusible cyan dye, a green-sensitive silver halide emulsion layerhaving associated therewith a magenta dye image-providing materialcomprising a nondiffusible coupler capable of reacting with oxidizedaromatic primary amino color developing agent to produce a diffusiblemagenta dye, and a blue-sensitive silver halide emulsion layer havingassociated therewith a yellow dye image-providing material comprising anondiffusible coupler capable of reacting with oxidized aromatic primaryamino color developing agent to produce a diffusible yellow dye; saidfilm unit containing an aromatic primary amino color developing agent.2. LINK is a connecting radical selected from the group consisting of anazo radical, a mercuri radical, an oxy radical, an alkylidene radical, athio radical, a dithio radical and an azoxy radical;
 3. COUP is acoupler radical selected from the group consisting of a 5-pyrazolonecoupler radical, a pyrazolotriazole coupler radical, a phenolic couplerradical and an open-chain ketomethylene coupler radical, said COUP beingsubstituted in the coupling position with said LINK;
 3. The film unit ofclaim 1 wherein said dye image-receiving layer is located in saidphotosensitive element between said support and the lowermostphotosensitivE silver halide emulsion layer, and said light-reflectinglayer is located in said photosensitive element between said dyeimage-receiving layer and said lowermost photosensitive silver halideemulsion layer.
 4. The film unit of claim 1 wherein said dyeimage-receiving layer is coated on a separate support and is adapted tobe superposed on said photosensitive element after exposure thereof, andsaid light-reflecting layer is located between said dye image-receivinglayer and its said support.
 4. BALL is a photographically inert organicballasting radical of such molecular size and configuration as to rendersaid coupler nondiffusible during development in said alkalineprocessing composition;
 5. SOL is selected from the group consisting ofa hydrogen atom and an acidic solubilizing group when said colordeveloping agent con-tains an acidic solubilizing group, and SOL is anacidic solubilizing when said color developing agent is free of anacidic solubilizing group; and
 5. The film unit of claim 4 wherein saidrupturable container is so positioned during processing of said filmunit that a compressive force applied to said container by saidpressure-applying members will effect a discharge of the container''scontents between said dye image-receiving layer and the outermost layerof said photosensitive element.
 6. The film unit of claim 1 which alsocontains a pH-lowering material.
 6. n is an integEr of 1 to 2 when saidLINK is an alkylidene radical, and n is 1 when said LINK is a radicalselected from the group consisting of an azo radical, a mercuri radical,an oxy radical, a thio radical, a dithio radical and an azoxy radical;II. a dye image-receiving element comprising a support having thereon adye image-receiving layer, said element being adapted to be superposedover said blue-sensitive silver halide emulsion layer after exposure ofsaid photosensitive element; and III. a rupturable container containingan alkaline processing composition and which is adapted to be positionedduring processing of said film unit so that a compressive force appliedto said container by said pressure-applying members will effect adischarge of the container''s contents between said dye image-receivinglayer and said blue-sensitive silver halide emulsion layer of saidphotosensitive element; said film unit containing an aromatic primaryamino color developing agent; the improvement comprising employing assaid dye image-receiving element a support having thereon a polymericacidic material layer, a light-reflecting layer, comprising a vinylpolymer containing anionic solubilizing groups and an opacifying agent,and a dye image-receiving layer.
 7. The film unit of claim 1 whereinsaid opacifying agent is titanium dioxide.
 8. The film unit of claim 1wherein said vinyl polymer is a copolymer comprising units of acrylicacid, sulfoalkyl acrylate or sulfoalkyl methacrylate.
 9. The film unitof claim 1 wherein said vinyl polymer is copoly(ethylacrylate, acrylicacid, 2-acetoacetoxyethyl methacrylate), copoly(ethylacrylate, acrylicacid) or copoly(n-butyl acrylate, 3-acryloxypropane-1-sulfonic acidsodium salt, 2-acetoacetoxy ethyl methacrylate).
 10. In a photographicfilm unit which is adapted to be processed by passing said unit betweena pair of juxtaposed pressure-applying members comprising: I. aphotosensitive element comprising a support having thereon the followinglayers in sequence: a. a direct-positive, red-sensitive silver halideemulsion layer containing a nondiffusible coupler capable of reactingwith oxidized aromatic primary amino color developing agent to produce adiffusible cyan dye; b. an alkaline solution-permeable interlayercontaining a compound capable of scavenging oxidized aromatic primaryamino color developing agent; c. a direct-positive, green-sensitivesilver halide emulsion layer containing a nondiffusible coupler capableof reacting with oxidized aromatic primary amino color developing agentto produce a diffusible magenta dye; d. an alkaline solution-permeableinterlayer containing a compound capable of scavenging oxidized aromaticprimary amino color developing agent; and e. a direct-positive,blue-sensitive silver halide emulsion layer containing a non-diffusiblecoupler capable of reacting with oxidized aromatic primary amino colordeveloping agent to produce a diffusible yellow dye; each saidnondiffusible coupler having the formula: DYE - LINK -(COUP - BALL)n orBALL - LINK - (COUP - SOL)n wherein:
 11. The photographic film unit ofclaim 10 wherein said vinyl polymer is a copolymer comprising units ofacrylic acid, sulfoalkyl acrylate or sulfoalkyl methacrylate and saidopacifying agent is titanium dioxide.
 12. The photographic film unit ofclaim 11 wherein said vinyl polymer is copoly(ethylacrylate, acrylicacid, 2-acetoacetoxyethyl methacrylate), copoly(ethylacrylate, acrylicacid) or copoly(n-butyl acrylate, 3-acryloxypropane-1-sulfonic acidsodium salt, 2-acetoacetoxy ethyl methacrylate).
 13. A reception elementcomprising a support having thereon a. a light-reflecting layercomprising a vinyl polymer containing anionic solubilizing groups and anopacifying agent, and b. a dye image-receiving layer.
 14. The receptionelement of claim 13 which includes a pH-lowering layer between saidsupport and said layer a.
 15. The reception element of claim 13 whereinsaid opacifying agent is titanium dioxide.
 16. The reception element ofclaim 13 wherein said vinyl polymer is a copolymer comprising units ofacrylic acid, sulfoalkyl acrylate or sulfoalkyl methacrylate.
 17. Thereception element of claim 16 wherein said vinyl polymer iscopoly(ethylacrylate, acrylic acid, 2-acetoacetoxyethyl methacrylate),copoly(ethylacrylate, acrylic acid) or copoly(n-butyl acrylate,3-acryloxypropane-1-sulfonic acid sodium salt, 2-acetoacetoxy ethylmethacrylate).
 18. The reception element of claim 17 wherein saidopacifying agent is titanium dioxide.
 19. In a process of forming atransfer image comprising: a. imagewise-exposing a photosensitiveelement comprising a support having thereon at least one photosensitivesilver halide emulsion layer, each said silver halide emulsion layerhaving associated therewith a dye image-providing material; b. treatingthe layer outermost from the support of said exposed photosensitiveelement with an alkaline processing compo-sition to effect developmentof each of said exposed silver halide emulsion layers; c. forming animagewise distribution of diffusible dye image-providing material as afunction of said imagewise exposure of each said silver halide emulsionlayer; and d. at least a portion of each said imagewise distribution ofdiffusible dye image-providing material diffusing to a dyeimage-receiving layer having a light-reflecting layer associatedtherewith; the improvement comprising employing as said light-reflectinglayer a vinyl polymer containing anionic solubilizing groups and anopacifying agent.
 20. The process of claim 19 wherein said treatmentstep b. is effected by A. superposing over the layer outermost from thesupport of said photosensitive element sAid dye image-receiving layercoated on a support, said light-reflecting layer being located betweensaid dye image-receiving layer and its said support; B. positioning arupturable container containing said alkaline processing compositionbetween said exposed photosensitive element and said dye image-receivinglayer; and C. applying a compressive force to said container to effect adischarge of the container''s contents between said outermost layer ofsaid exposed photosensitive element and said dye image-receiving layer.21. The process of claim 20 wherein said vinyl polymer is a copolymercomprising units of acrylic acid, sulfoalkyl acrylate or sulfoalkylmethacrylate.
 22. The process of claim 21 wherein said vinyl polymer iscopoly(ethylacrylate, acrylic acid, 2-acetoacetoxyethyl methacrylate),copoly(ethylacrylate, acrylic acid) or copoly(n-butyl acrylate,3-acryloxypropane-1-sulfonic acid sodium salt, 2-acetoacetoxy ethylmethacrylate).